JP2007090214A - Ship ballast water production method and apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a ship ballast water production method and apparatus which can efficiently remove both plankton and bacteria in seawater in a harbor area in which a ship is anchored by a method other than killing them, and reduce the installation area of the whole apparatus. <P>SOLUTION: In the ship ballast water production method and the apparatus used for it, primary treated water obtained by removing plankton in the seawater in which the ship is anchored with a plankton filter membrane is stored in a ballast tank, and then secondary treated water obtained by removing bacteria in the stored primary treated water with a bacteria filter membrane is stored in the ballast tank as ballast water during a voyage. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for producing marine ballast water for removing planktons and bacteria in marine ballast water (hereinafter, also simply referred to as “ballast water”) loaded to stabilize the center of gravity during navigation of the marine vessel, and It relates to a manufacturing apparatus.

  Crude oil tankers, ore carriers, car carriers, bulk carriers, etc. may sail with little or no cargo. At that time, the hull is lifted by buoyancy, and the screw and rudder are not submerged under the surface of the water, or the hull on the surface of the water is greatly affected by the wind and the maneuverability is impaired, making it extremely dangerous for navigation. For this reason, in order to adjust the buoyancy at the time of navigation, a normal ship carries a ballast water of 30 to 40% by weight of a normal load weight.

  For example, transportation by crude oil tankers is a round trip between oil-producing countries and consuming countries, and there is no cargo when navigating from consuming countries to oil-producing countries. It is water. On the other hand, a ship loaded with ballast water discharges ballast water in the sea near the oil producing country or at a port and carries crude oil.

  In recent years, ballast water discharged from ships has brought planktons and bacteria that do not inherently live in specific waters, resulting in the destruction of marine ecosystems and only causing serious damage to the lives of the people living in those waters. Rather, it has caused the destruction of the global marine environment, which is a serious international problem. Under these circumstances, in February 2004, the International Maritime Organization (IMO) adopted the “Ballast Water and Sediment Emission Standards” in deliberation of the “Ballast Water Management Convention”. In addition, the emission standards stipulated regulated substances such as planktons and bacteria in ballast water.

  Of these regulated substances, several techniques have been proposed in the past for the removal of planktons. For example, the “special pipe” developed by the Japan Marine Accident Prevention Association is a method in which seawater is passed through slit plates stacked in multiple layers, and planktons are destroyed and killed at that time. Annual Fall Meeting Proceedings 35-40). In addition, the plankton removal method disclosed in the Journal of Ocean Science and Technology Fall 2003 Annual Meeting 73-78 is a method of removing planktons by filtration using a metal filter having a pore diameter of 5 μm or more. However, even if planktons can be killed or removed by these methods, bacteria smaller than planktons cannot be removed effectively.

  Moreover, as a method of removing bacteria in seawater pumped as ballast water, for example, a method of killing bacteria by heating seawater (Japanese Patent Laid-Open No. 2003-181443), a method of irradiating bacteria with ultraviolet rays A method of inactivating aldehydes (Japanese Patent Publication No. 2000-515803, Japanese Patent Application Laid-Open No. 11-265684), a method of treating with iodine (Japanese Patent Publication No. 2002-504851), and a method of treating with hypochlorous acid (Special (Kaihei 04-322788) and the like have been proposed.

  However, the method of heating seawater is not economical depending on the means for obtaining heating energy, and it is difficult to completely kill bacteria. In addition, the method of irradiating seawater with ultraviolet rays requires enormous amounts of power to kill or inactivate all bacteria, and in order to treat high-flow seawater, many UV devices are installed in parallel. Increase the installation cost of the equipment. In addition, the method of treating seawater with chemicals such as iodine and hypochlorous acid requires a high concentration of chemicals to kill them depending on the type of bacteria, which is not economical and is contained in the discharged ballast water. There are also problems with the environmental impact of residual drugs.

  As described above, the method of killing bacteria in seawater is difficult to completely kill bacteria, and there is a concern about the impact of contamination by carcasses on the ecosystem. Furthermore, since a small amount of bacteria that remain without being killed grow during transportation, development of a method for completely removing these bacteria is eagerly desired. As such a technique, a ship provided with a ballast water purification device using a filtration drum having an opening of 20 μm or less has been proposed (Japanese Patent Laid-Open No. 2005-88835). However, in this ballast water purification apparatus, a metal or plastic mesh is used as the filter, but the lower limit of the pore diameter of the mesh is 2 to 3 μm, and it is not possible to sufficiently remove bacteria. There is.

Moreover, although the method of removing bacteria in seawater by letting seawater pass through a microfiltration membrane is also known (Japanese Patent Laid-Open No. 2003-154360), the membrane filtered water obtained by this method is used for washing seafood, etc. It is not used for ship ballast water. Moreover, even if the bacteria in the seawater are removed with a microfiltration membrane to obtain ballast water, the ballast water is loaded while the ship is anchored in the port where the ship unloads, so the seawater treatment capacity Therefore, there is a problem that the equipment becomes large, and it becomes easy to cause difficulty in loading in a limited ship space.
Ocean Science and Technology Society 2005 Fall Conference Proceedings 35-40 Ocean Science and Technology Society 2003 Autumn Conference Lecture Collection, pp. 73-78 JP 2003-181443 A Special Table 2000-515803 JP-A-11-265684 Japanese translation of PCT publication No. 2002-504851 Japanese Patent Laid-Open No. 04-322788 JP 2005-88835 A JP 2003-154360 A

  Therefore, an object of the present invention is to efficiently remove planktons and bacteria in seawater in a harbor area where a ship is anchored by a method other than the method of killing both, and to reduce the installation area of the entire apparatus. It is providing the manufacturing method and manufacturing apparatus of the ballast water for ships.

  Under such circumstances, the present inventors have conducted extensive studies, and as a result, (1) plankton is removed by removing planktons and bacteria in seawater used as ballast water with a two-stage filtration device having different pore diameters. (2) While the ship is unloading at the port where the ship is unloaded, seawater is loaded into the ballast tank as primary treated water through the plankton removal membrane, and after the departure During the voyage, the primary treatment water in the ballast tank can be circulated through a device using a bacteria removal membrane, so that the overall size of the device can be greatly reduced. (3) Characteristics of bacteria in the ballast tank In the dark room such as a ballast tank, the growth of the bacteria is suppressed and further reduced. (4) The filtration process of bacteria can be further reduced in size due to the synergistic effect of the long-term treatment during the voyage of the ship and the reduction effect of the bacteria. The headline and the present invention were completed.

  That is, the present invention (1) is the primary treatment stored during the voyage after storing the primary treated water from the plankton in the seawater of the harbor area where the ship is anchored by the plankton filtration membrane in the ballast tank. The present invention provides a method for producing ballast water in which secondary treated water obtained by removing bacteria in water with a bacteria filtration membrane is stored in the ballast tank as ballast water.

  In addition, the present invention (2) includes a filtration device including a filtration membrane having a pore diameter of 2 μm or more for removing planktons in seawater in a harbor area where a vessel is anchored, and seawater treated by the filtration device in a ballast tank for a vessel. A first introduction means to be introduced into the filter, a filtration device comprising a filtration membrane having a pore diameter of less than 1 μm for removing bacteria in seawater in the ballast tank from which plankton has been removed, and a filtration device comprising a filtration membrane having a pore diameter of less than 1 μm There is provided a marine ballast water production apparatus having second introduction means for introducing treated seawater into a marine ballast tank.

  According to the present invention, planktons and bacteria in seawater used as ballast water are removed by a two-stage filtration device having different pore diameters, so that regulated substances such as planktons and bacteria can be effectively removed. Conventionally, when untreated raw seawater is once loaded into a ballast tank, there has been a problem that the inner wall of the ballast tank is contaminated by an adhesive substance (slime) that is thought to be derived from plankton in the raw seawater. The seawater is loaded into the ballast tank as the primary treatment water through the plankton removal membrane, so that the inner wall of the ballast tank is not contaminated, and after the departure, the primary treatment water in the ballast tank is bacteria. Since the circulation treatment is performed through the removal membrane, the size of the filtration device including the bacteria removal membrane can be greatly reduced. In addition, the filtration process of bacteria is further reduced in size due to a synergistic effect that bacteria do not self-grow in the dark seawater and can be treated for a long time while sailing. Can be downsized.

  In the method for producing ballast water of the present invention, the seawater in the harbor area where the ship is anchored is not particularly limited, but is seawater having a turbidity of 1 to 100 degrees in addition to planktons and bacteria. In the present invention, plankton refers to those having a size of 10 μm or more, and means plankton usually classified into phytoplankton and zooplankton, as well as larvae and eggs of seafood. Specific examples of planktons include daphnia larvae, North Pacific starfish larvae, Asian kelp larvae, zebra clam larvae, and toxic algae. In the present invention, examples of bacteria include Escherichia coli, Vibrio cholerae, Enterococcus and the like. The size of bacteria is smaller than that of planktons, the smallest being about 0.3 to 0.5 μm.

  In the method for producing ballast water of the present invention, examples of the plankton filtration membrane include filtration membranes having a pore diameter of 2 μm or more and usually 2 to 20 μm. Although it does not specifically limit as filtration with a hole diameter of 2 micrometers or more, A metal filtration membrane, an organic filtration membrane, etc. are mentioned, Among these, a metal filtration membrane is preferable. Filters using organic filtration include, for example, a wind-type cartridge filter wound with polypropylene or the like, a cartridge filter in which a nonwoven fabric or a membrane filter is folded in a pleat shape, and a slit-shaped groove inclined at a predetermined angle with respect to the radial direction. An element body formed by laminating a ring-shaped flat plate made of polypropylene having s. Of these, the cartridge type is usually not backwashed and is not disposable because it is disposable, and the replacement operation is complicated and unsuitable as a loading device. In addition, the laminated element body has a drawback that the filtration area per apparatus volume is small and the apparatus space is increased because only the slit-shaped grooves formed by stacking ring-shaped flat plates are filtered. On the other hand, the metal filtration membrane can increase the strength and increase the filtration speed, so that the device can be made compact with a device size of about 1/5 to 1/10 compared with the organic filtration membrane. It is preferable in that the membrane surface can be cleaned by a simple method using hot water or steam.

  The pore diameter of the metal filtration membrane is displayed as a nominal value, and for example, a nominal pore diameter of 2.5 μm to 20 μm is suitable. The upper limit of the pore size of the filter membrane used in the plankton removal device is not particularly limited, but if it is too large, the plankton removal performance is degraded, and clogging of the subsequent bacterial filtration membrane is promoted. Usually, it is 50 μm.

  Although it does not restrict | limit especially as a metal filtration membrane, The mesh-like filter etc. which laminated | stacked and fixed the several sheets of the mesh-like sheet body etc. which laminated | stacked and sintered the felt of metal fibers of corrosion-resistant metal, such as stainless steel, etc. are mentioned. A filtration apparatus incorporating such a metal filtration membrane is usually of a total volume filtration type. In addition, if the rotary filtration device is provided with a cylindrical metal filtration membrane around the pipe-shaped axis that is the filtrate discharge pipe and excretes the jet port of the high-speed jet flow close to the metal filtration membrane surface, Planktons collected on the membrane surface while performing continuous water flow can be frequently washed with a high-speed water flow, which is preferable in that the filtration time can be shortened. Further, the plankton removal rate in the plankton removal device of the present invention is not particularly limited, but a higher removal rate is preferable in that it does not adversely affect clogging of the subsequent bacterial filtration membrane.

  The primary treated water from which planktons in seawater have been removed with a plankton filter membrane is sent and stored in a ballast tank. Ships' ballast tanks are becoming double-hulled, and a plurality of ballast tanks are installed for each ship. For this reason, primary treated water is stored in a part or all of the ballast tank. The amount of ballast water stored varies depending on the amount of cargo loaded on the ship, and the amount of ballast tank to be stored and the amount stored in each ballast tank are appropriately determined. The plankton filtration process in seawater treats a large amount of seawater while the ship is anchored, but the plankton filtration membrane has a relatively large pore size and can increase the filtration rate, so it is equipped with a plankton filtration membrane. The device size does not increase. As before, when unprocessed raw seawater is once loaded into an empty ballast tank, the inner wall of the ballast tank is contaminated by an adhesive substance (slime) that may be derived from plankton in the raw seawater, and the ballast water is discharged. Although there existed a problem that it remained afterward, since this invention loads the primary treated water from which the planktons in seawater were removed previously in a ballast tank, this problem can be eliminated.

  Next, during the voyage, the secondary treated water obtained by removing the bacteria in the stored primary treated water with a bacteria filtration membrane is stored in the ballast tank as ballast water. If seawater is passed directly through a bacterial filtration membrane, both plankton and bacteria can be removed, but frequent backwashing may be necessary, or the filtration membrane may become clogged and become unable to regenerate early. In particular, when a hollow fiber membrane is used as a bacterial filtration membrane, the pore size is 1 μm or less and the treatment flow rate cannot be increased so much, so that it is necessary to increase the membrane area to increase the treatment capacity. The device is inevitably excessive. On the other hand, in the bacterial filtration step of the present invention, planktons and other foreign matters in the seawater are previously removed by the plankton filtration membrane, and the primary treated water roughly removed in the bacterial filtration step is used. Since the treatment is performed with a bacteria filtration membrane, the filtration efficiency is improved. In addition, since the bacteria filtration step is performed during a long voyage, it can be processed over time, and the size of the bacteria filtration membrane device can be reduced.

  Although the primary treated water stored in the ballast tank contains bacteria such as Escherichia coli, enterococci, and cholera bacteria, it is stored in the dark room, so that bacteria self-growth does not occur but rather decreases. In addition, since Escherichia coli, enterococci, cholera bacteria and the like are not originally derived from seawater, self-growth is suppressed even if left in seawater. Therefore, the attenuation of bacteria in the primary treated water stored in the ballast tank becomes more remarkable, and the filtration process of bacteria is performed by circulating the stored water in the ballast tank to the bacteria filtration membrane. The decay of such bacteria is further accelerated and is no longer detected, for example in a few days. For this reason, the apparatus size provided with the bacteria filtration membrane can be further reduced.

  As the bacterial filtration membrane, a filtration membrane having a pore diameter of less than 1 μm can be used. Specific examples include microfiltration membranes (MF) such as hollow fiber membranes, flat membranes and tubular membranes, and ultrafiltration membranes (UF). It is done. Among these, the hollow fiber membrane is preferable in that the filtration area per unit volume can be maximized.

  The hollow fiber membrane has a large number of hollow fibers arranged in parallel, has a hollow structure, and further communicates with the holes forming the hollow structure, and has many pores communicating with the holes on the membrane surface. There are external pressure type and internal pressure type. In the present invention, when a microfiltration membrane is used as the bacterial filtration membrane, the pore diameter of the hollow fiber membrane is 0.01 to 0.4 μm, preferably 0.01 to 0.3 μm. Moreover, when using an ultrafiltration membrane, it is 0.002-0.01 micrometer as a diameter of the pore of a hollow fiber membrane. The size of bacteria in seawater is usually several microns, and the smallest is about 0.3 to 0.5 μm. Therefore, if hollow fiber membranes with the above pore diameter are specified, these bacteria in seawater are It can be removed almost completely. In addition, backwashing is performed to remove bacteria attached to the membrane surface and restore its filtration capacity. Separately from this backwashing, the membrane is bubbled with bubbles from the outside of the membrane surface during filtration. It is preferable to use an external pressure type hollow fiber membrane from the viewpoint that an operation of peeling and removing bacteria attached to the surface can be performed.

  The hollow fiber membrane is used as a pressure type hollow fiber membrane device or an immersion type hollow fiber membrane device. The method using a pressurized hollow fiber membrane device is a method for removing bacteria in seawater by supplying seawater with a pressure pump loaded in a pressure vessel. The method using the submerged hollow fiber membrane device is a method of removing bacteria in the seawater by sucking the inside of the hollow fiber of the device immersed in the seawater reservoir with a suction pump.

  Examples of the material for the microfiltration membrane include polyethylene, polypropylene, polyvinyl alcohol, polysulfone, polyvinylidene chloride, polyvinylidene fluoride, chlorinated polyethylene, chlorinated polypropylene, polyacrylonitrile, and cellulose acetate.

  In the bacterial filtration treatment step of the present invention, a step of washing the bacterial filtration membrane by back washing may be performed. In the bacterial filtration process, as time elapses, bacteria that cause clogging of the membrane adhere to the bacterial filtration membrane and the membrane differential pressure increases at the inlet and outlet of the membrane. For this reason, the filtration of seawater is stopped, and the bacterial filtration membrane is backwashed using the membrane filtration water as washing water. By performing the backwashing step, the filtration function of the bacterial filtration membrane is restored. When the backwashing process is completed, the process moves to the bacteria filtration process again, and this is repeated to enable filtration for a long time. In the present invention, the planktons and other floating substances are roughly removed by the preceding filtration membrane, so that clogging of the subsequent bacteria filtration membrane is suppressed. For this reason, the time for performing backwashing can be shortened, and the amount of processing per unit time can be increased.

  The ballast water production method of the present invention performs plankton filtration while the ship is anchored, and filters bacteria in the treated water during the voyage. A planktons filtration process may be performed, followed by a bacteria filtration process followed by a process of sending treated water from which both planktons and bacteria have been removed to the ballast tank. Thus, for example, if there is a margin in the berthing time of the ship, planktons filtration processing is performed first, most of the primary treatment water is obtained, and then the above-mentioned direct continuous treatment is performed for the remaining time. Thus, effective use of time can be achieved, and the primary treated water in the ballast tank can be reduced in bacteria.

  A ballast water production apparatus for a ship according to the present invention is installed in a ship, and includes a filtration apparatus having a filtration membrane having a pore diameter of 2 μm or more for removing planktons in seawater in a harbor area where the ship is anchored, and the filtration First filtration means for introducing seawater treated by the apparatus into a marine ballast tank; a filtration apparatus comprising a filtration membrane having a pore diameter of less than 1 μm for removing bacteria in seawater in the ballast tank from which plankton has been removed; And a second introduction means for introducing seawater treated by a filtration apparatus including a filtration membrane having a pore diameter of less than 1 μm into a marine ballast tank. Examples of the filtration apparatus including a filtration membrane having a pore diameter of 2 μm or more for removing planktons and the filtration apparatus having a filtration membrane having a pore diameter of less than 1 μm for removing bacteria include those similar to those in the above-described method for producing ballast water.

Next, an example of the ship ballast water production apparatus of the present invention will be described with reference to FIG. FIG. 1 is a flowchart of the ballast water production apparatus. In FIG. 1, a ballast water production apparatus 10 has a filtration apparatus (hereinafter referred to as a plankton filtration membrane apparatus) including a pump 1 and a filtration membrane having a pore diameter of 2 μm or more for removing planktons in seawater from the upstream side toward the downstream side. 2) A filtration device (hereinafter referred to as a bacteria filtration membrane device) 3 and a ballast tank 4 provided with a filtration membrane having a pore diameter of less than 1 μm for removing bacteria in seawater. Ballast tank 4 is, in this example has seven chambers _B 1 .about.B _7.

  In the ballast water production apparatus 10, a seawater intake pipe 11 is connected to the suction side of the pump 1, the pump 1 and the plankton filtration membrane apparatus 2 are the pipe 12, and the plankton filtration membrane apparatus 2 and the bacteria filtration membrane apparatus 3 are In the pipe 13, the bacteria filtration membrane device 3 and the ballast tank 4 are connected by a pipe 14 and a branch pipe group 18, respectively. The ballast water production apparatus 10 includes a pipe 15 that bypasses the plankton filtration membrane apparatus 2 that directly connects the pipe 12 and the pipe 13, and the pipe 13 and the pipe 14 on the upstream side of the connection point between the pipe 13 and the pipe 15. The piping 11 bypassing the bacterial filtration membrane device 3 is directly connected, and the branch piping group 19 serving as the outflow piping of the ballast tank 4 and the piping 11 are connected by a return piping 17. Valves are appropriately arranged in each of these piping groups. In the ballast water production apparatus 10, the first introduction means refers to the pump 1, the pipe group, and the valve group that introduce seawater treated by the plankton filtration membrane apparatus 2 into the ballast tank 4, and the second introduction means includes the ballast tank. The pump 1, the piping group, and the valve group which introduce | transduce the seawater which processed the primary treated water in 4 by the bacteria filtration membrane apparatus 3 in the ballast tank 4 are said.

In order to produce ballast water using the ballast water production apparatus 10, first, seawater in the harbor area where the ship is anchored is pumped by the pump 1 and passed through the plankton filtration apparatus 2. At this time, the valves 21 and 23 are opened, and the valves 22 and 24 are closed. Next, the primary treated water plankton in sea water with plankton filtering device 2 has been removed is supplied to the ballast tank partition tank B _1. At this time, the valves 26 and 31 are opened, and the valves 25, 32 to 37, and valves 41 to 47 are closed. When ballast tanks partition tank B ₁ is full, the valve 31 closed, as the valve 32 opens, the seawater after plankton removal fed to the ballast tank partition tank B _2, sequentially the operation and B _3, B ₄ · · performed, all B ₇ from the ballast tank partition tank B _1, filled with primary treatment water after plankton removal. The plankton filtration process is performed while the ship is unloading the cargo.

Then, during the ship voyage, the primary treated water ballast tanks partition tank B ₁ performs removal operations bacteria such through bacteria such filtration device 3, and feeding the filtered water into the ballast tank partition tank B _1, The membrane filtration process which circulates this is performed. In this bacteria filtration step, the valves 41, 22, 24, 31 are opened and the valves 21, 23, 25 are closed. Also in this bacteria filtration step, after the treatment of the partition tank B ₁ is completed, this operation is sequentially performed as B ₂ , B ₃ ..., And the bacteria are removed from all of the ballast tank partition tanks B ₁ to B _7. Fill with fresh seawater. Bacterial filtration process can be performed during long voyages of the ship, membrane filtration by circulation treatment should be performed, and bacteria in the primary treatment water may be attenuated. Equipment is enough. For this reason, it is suitable for the installation on the ship where installation space is restricted. Moreover, the size of the entire ballast water production apparatus can be reduced, and the equipment cost can be reduced. The manufacturing method of ballast water according the above example embodiments is a method for sequentially utilizing B ₇ from the partition tank B _1, it is not limited to this, as to open the valve 31 to 37 at the same time, all at once A method of supplying treated water to the partition tank may be used.

In addition, while the vessel is anchored, the plankton filtration process is performed. Before and after the plankton filtration process, preferably after the plankton filtration process, the primary treated water that has passed through the plankton filtration apparatus 2 is not sent to the ballast tank 4, You may implement the continuous process process which sends the filtered water to the ballast tank 4 as it is through the bacteria filtration apparatus 3 as it is. Taking a case of supplying the ballast water to the partition tank B ₁ as an example, for example, by supplying most of the primary treated water partition tank B ₁ by plankton filtration process, the valve 26 closed, and the valve 25 opened, plankton Filtration step and subsequent bacteria filtration step are continuously performed. Thereby, when there is a time allowance for berthing of a ship, time can be used effectively.

  Although it does not specifically limit as a ship used as the object of installation by this invention, For example, a crude oil tanker, an ore carrier ship, an automobile carrier ship, a bulk carrier etc. are mentioned.

  EXAMPLES Next, although an Example is given and this invention is demonstrated further more concretely, this is only an illustration and does not restrict | limit this invention.

  Seawater (hereinafter referred to as “raw seawater”) in port A in Japan where the ship is anchored was treated under the following operating conditions using the ballast water production apparatus of FIG. The number of coliforms in the raw seawater and the water (membrane filtered water) in the ballast water storage tank after the predetermined time treatment was measured by the following measuring method. As a result, the number of coliforms was 100/100 ml. This number of coliforms satisfied the International Maritime Organization (IMO) ballast water treatment standards. The raw seawater was collected from a depth of 3 m from the sea surface. Its turbidity was 2 degrees, the total plankton number was 5000/100 ml or more, and the number of coliforms was 1500/100 ml.

(Ballast water production equipment)
The apparatus shown in FIG. 2 was used. The ballast water production apparatus 20 is a simulation experiment apparatus in which the ballast water production apparatus 10 in FIG. 1 is replaced with the ballast tank 4 constituted by the partition tanks B _{1 to} B ₇ , and a single ballast water storage tank 4 a is used.

(Plankton filtration membrane device)
One metal filter ("Fuji Metal Fiber Filter"; manufactured by Fuji Filter Industry Co., Ltd.) made of stainless steel having a fractional pore diameter of 3 μm (nominal) and having a diameter of 1.4 cm, a length of 20 cm, and an effective membrane area of 85 cm ² was used.

(Bacteria filtration membrane device)
A hollow fiber element ("Sterapore"; manufactured by Mitsubishi Rayon Co., Ltd.) having an outer diameter of 5 cm, a length of 44 cm, and an effective membrane area of 0.2 m ² made of 0.1 μm polyethylene and bundled with hollow fibers having an outer diameter of 0.51 mm is used. did.

(how to drive)
Plankton filtration step: In the ballast water production apparatus 20 of FIG. 2, the valves 21, 23, and 26 were opened, and the valves 22, 24, and 25 were closed. Next, the raw sea water is passed through the plankton filtration membrane device 2 by the pump 1 at a treatment flow rate of 0.6 m ³ / day for 6 hours, the bacteria filtration membrane device 3 is bypassed, and the treated water is stored in the ballast water storage tank 4a. Water was sent to

  Bacteria filtration step: In the ballast water production apparatus 20 of FIG. 2, the valves 22 and 24 were opened and the valves 21, 23, 25 and 26 were closed. Next, the bacterial filtrate was extracted from the ballast water storage tank 4a, bypassed the plankton filtration membrane device 2 through the pump 1, and directly passed through the bacterial filtration membrane device 3, which was repeatedly circulated. This circulation treatment was carried out continuously for 36 hours.

(Method of measuring coliform bacteria)
The number of colonies was measured according to “Test method for coliform bacteria in JISK0350-20-10 water / drainage”.

Reference example 1
In the ballast water production apparatus 20 of FIG. 2, the valves 21, 23, and 25 are open, and the valves 22, 24, and 26 are closed. That is, in Reference Example 1, raw seawater is subjected to continuous water passing treatment in the order of plankton filter membrane device 2 and bacteria filter membrane device 3. The plankton filter membrane device 2 and the bacteria filter membrane device 3 were of the following specifications. As a result, the number of coliforms was 10/100 ml. This number of coliforms satisfied the International Maritime Organization (IMO) ballast water treatment standards.

(Plankton filtration membrane device)
^Two metal filters ("Fuji Metal Fiber Filter"; manufactured by Fuji Filter Industrial Co., Ltd.) made of stainless steel having a fractional pore diameter of 3 μm (nominal) and having a diameter of 1.4 cm, a length of 20 cm, and an effective membrane area of 85 cm ² were used.

(Bacteria filtration membrane device)
A hollow fiber element ("Sterapore"; manufactured by Mitsubishi Rayon Co., Ltd.) having an outer diameter of 5 cm, a length of 44 cm, and an effective membrane area of 0.4 m ² made of 0.1 μm polyethylene and bundled with hollow fibers having an outer diameter of 0.51 mm is used. did.

(how to drive)
The raw seawater was subjected to continuous water passing treatment for 3 hours at a treatment flow rate of 1.2 m ³ / day in the order of plankton filtration membrane device 2 and bacterial filtration membrane device 3.

According to Example 1, the ballast water which removed efficiently by methods other than the method of killing together planktons and bacteria in the seawater of the harbor area where a ship anchors can be manufactured. Further, when Example 1 and Reference Example 1 are compared and compared, the effective membrane area of the hollow fiber membrane which is a bacterial filtration membrane is 0.2 m ² in Example 1, whereas 0.4 m in Reference Example 1 ^In Example 1, compared to Reference Example 1, the area of the hollow fiber membrane used could be halved, and the apparatus could be downsized.

It is a flowchart of an example of the ballast water manufacturing apparatus for ships of this invention. It is a flowchart of the ballast water manufacturing apparatus for ships used in Example 1.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Pump 2 Plankton filter membrane apparatus 3 Bacteria filter membrane apparatus 4 Ballast tank 4a Ballast water storage tank 10, 20 Ballast water production apparatus 11-17 Piping 18, 19 Branch piping group 21-26, 31-37, 41-47 valve _B 1 .about.B ₇ partition tank

Claims (10)

  After storing the primary treated water from the plankton in the seawater in the harbor area where the ship is anchored with a plankton filtration membrane in the ballast tank, the bacteria in the stored primary treated water are filtered during the voyage. A method for producing marine ballast water, wherein the secondary treated water removed by the membrane is stored in the ballast tank as ballast water.   The method for producing marine ballast water according to claim 1, wherein the filtration treatment using the bacteria filtration membrane is a treatment performed by circulating the stored water in the ballast tank to the bacteria filtration membrane.   The method for producing marine ballast water according to claim 1 or 2, wherein the plankton filtration membrane is a metal membrane having a pore diameter of 2 µm or more.   The method for producing marine ballast water according to any one of claims 1 to 3, wherein the bacterial filtration membrane is a hollow fiber membrane.   The method for producing marine ballast water according to any one of claims 1 to 4, further comprising a backwashing step of washing the bacteria filtration membrane by backwashing.   A filtration device including a filtration membrane having a pore diameter of 2 μm or more for removing planktons in seawater in a harbor area where a ship is anchored; and first introduction means for introducing seawater treated by the filtration device into a ballast tank for ships; Ballasts for marine vessels treated with a filtration device having a filtration membrane having a pore diameter of less than 1 μm for removing bacteria in seawater in the ballast tank from which planktons have been removed, and a filtration device having a filtration membrane having a pore diameter of less than 1 μm A ship ballast water production apparatus comprising: a second introduction means for introducing the tank into the tank.   By connecting a filtration apparatus having a filtration membrane having a pore diameter of 2 μm or more in the front stage and a filtration apparatus having a filtration membrane having a pore diameter of less than 1 μm in the subsequent stage, and by using a filtration apparatus having a filtration membrane having a pore diameter of less than 1 μm in the latter stage, The apparatus for producing ballast water for a ship according to claim 6, wherein treated water of a filtration device including a filtration membrane having a pore diameter of 2 μm or more is treated.   The apparatus for producing marine ballast water according to claim 6 or 7, wherein the filtration membrane having a pore diameter of 2 µm or more is a metal filtration membrane.   The apparatus for producing ballast water for ships according to any one of claims 6 to 8, wherein the filtration membrane having a pore diameter of less than 1 µm is a hollow fiber membrane.   The apparatus for producing marine ballast water according to any one of claims 6 to 9, further comprising backwashing means for washing a filtration membrane having a pore diameter of less than 1 µm by backwashing.

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